Conversores CC-CC de elevado ganho baseados na topologia boost empregando indutores acoplados e células multiplicadoras de tensão

Abstract

Currently, the search for the use of sustainable energy sources such as solar energy, wind power and fuel cells has increased, in an attempt to reduce environmental problems. However, energy production through renewable sources generates low voltage levels. Under this scenario, the use of DC-DC converters becomes fundamental. Thus, the electricity consumption from systems that generate energy in direct current (DC) is no longer an alternative but a necessity. However, for the produced energy be delivered for use in the proper form, a DC-DC converter, generally, should be employed. In this work, the study and the implementation of two high-gain DC-DC converters to condition the energy from DC generating sources such as photovoltaics and fuel cells are carried out. They are structures made up of only a single switch and based on the Boost-type converter using coupled inductors and voltage multiplier cells. Both topologies have as main features high efficiency, reduced blocking voltages on the switches and diodes, and reduced elements count. The proposed DC-DC converters are better suited for applications where the consumed power is in the order of a few units of hundreds of Watts, which corresponds to the power provided by a photovoltaic panel (PV). In order to understand both converters' behavior, as well as define a design procedure where all the elements can be designed and specified, the principles of operation at steady state are presented. In addition, in order to ensure a closed-loop system's operation, the dynamic analyses are also developed. Thus, the transfer function of each plant is determined and the control system can be properly designed. Simulation results for both proposed topologies operating with an input voltage of 48 V, switching frequency of 100 kHz, voltage and power rated of 400 V and 400 W, respectively, are also presented.